Exhaust temperature air-cooling system



l hl 6 A. M. CADDELL Filed Jan. 27, 1959 Hill il HU Il E lll lll EXHAUSTTEMPERATURE AIR-COOLING SYSTEM May 23, 1961 moN vor

United States Patent EXHAUST TEMPERATURE AIR-COOLING SYSTEM Alfred M.Caddell, 1318 W. Hunting Park Ave., Philadelphia 40, Pa.

Filed Jan. 27, 1959, Ser. No. 789,379

4 Claims. (Cl. S0-'30) The present application is in part a continuationof pending application entitled Internal-External Air Cooled Manifold,filed Dec. 30, 1954, Serial No. 478,793, now abandoned.

'I'his invention concerns a new type of exhaust system which may includea collector ring as used in radial internal combustion engines orutilize a straight-through form of manifold for employment with either astationary engine or an engine that powers an automobile or othervehicle, including marine craft.

The object of this invention is to reduce as simply and as fast aspossible the temperature of the exhaust gas before it reaches theatmosphere, thus making possible an increase in the power outputpotential that is now choked by mufing and other conflicting phenomenaherein described. In addition to such power increase, silencing of theexhaust automatically is achieved.

With the exception of those exhausting directly to atmosphere, everyengine known to this applicant is equipped with a muffler which stiflesnoise but, while doing so, stitles the engine as well. When a muiiier isemployed, the very force that drives a piston virtually remains pent upwhile it is being discharged. Back pressure results, putting a brake onpiston movement and, therefore, power output. Moreover, the resultingsacrifice in power involves a serious waste of fuel that was initiallyrequired to generate the energy. Compared to what it could be, even withthe best of engines equipped with a muier, the performance is sluggish.

Due to such incomplete exhausting, a considerable percentage of thetired gas remains in the cylinder to vitiate the incoming charge offresh fuel-air mixture. At present, the charge that does enter becomesrelatively impotent compared to the quantity and quality of the mixturethat otherwise could ll the cylinder. Therefore, by assisting in theremoval of dead gas, an increase in net power output automaticallyresults.

Further, by promoting more through combustion of the unburned gasdischarged with the exhaust, troublesome smog that covers city streetslike a blanket is prevented.

This irritating smog is caused by a part of the gas that is not burnedas it passes through an engine. As one example, cars idling in trafficdo not utilize all the gas delivered to the cylinders by the carburetor.Considerable of it emerges from the tail pipe as vapor or as partlyburned derivatives known as alhehydes which react with components of theatmosphere to produce new chemical compounds that weigh heavily andcontribute to the acrid quality of smog.

Creation of vacua When discharging openly to atmosphere without anyattempt at cooling and having high velocity, the exhaust slugsover-extend themselves, causing equally as high vacuums to form in theirwake. Just as instantly, these vacuums pull back some of the gas intothe pipe whence it came. This pull-back can be seen when exhaust gas isdirected through a Pyrex tube in the presence of titanium tetrachloridesmoke. After every discharge smoke flashes back in the tube to ll thecreated vacua, only to be met with the discharge of the next slug ofgas. This collision of forces translates into an obstacle that detractsgreatly from power output.

Exhaust silencing Still another phase of exhausting-that of silencinghasinterrelated power-consuming and audible discomfort effects. Whendischarging through open stacks, the exhaust slugs violently displaceair, causing vacuum pockets to form just outside the stacks. Action andreaction being equal and opposite, the instantaneous closing of thesepockets by air, which itself is under heavy static pressure, causes thewell-known thunderclap noises, the molecules of the air colliding witheach other at great speed. Aside from the wracking of nerves, theresulting vibration caused by such air collisions sets up standing wavesin the exhaust pipe lwhich reflect all the way back into the enginescylinders, there to be met by concussion waves generated by thenext-following explosion. This powerconsuming and noise-recurring cyclecontinues throughout the run of the engine.

The exhaust system described herein is designed to supplant a mutlierand thus avoid the drawbacks imposed by such a device upon the engine.

The system is comprised of an inner and an outer wall and a ductcontinuing as an extension of said outer Wall. Also, an entrance ductfor conveying air to the air-cooling part of the system. Each of saidmanifold walls and duct may be of round, square or other appropriateconstruction. They are separated from each other by spider means forpermitting the flow of air therebetween. A plurality of pipes, eachconnected to an exhaust port of an engine, convey exhaust gas to theinner gas-dow area of the system, which area is defined by the diameterof the inner wall. Part of the cooling air that enters the space betweenthe walls is intercepted by protruding portions of conduits mounted ininserts secured in the inner wall. Whereupon the air is conveyed towardthe center of the gas-iiow area by another portion of the conduits,which portions are designed to cause deflection of the gas therearoundand thus, through suction, superimpose the speed of the exhaust gas uponthe air. The result is a precipitous lowering of the temperature of thegas due to the admixture of cooling air therewith inside the inner wall.

In addition to the foregoing suction of air into the gas-ow area, meansare also provided to insure maximum suction of air through the spacebetween the inner and the outer walls.

Absorption of heat by convection, which provides for the rapid passageof air over a hot surface, is the best known means of extracting heatfrom an object, be it a stove or an exhaust manifold. Toward that end, aduct is provided as a continuation of the shroud wall and a rain-dropform of cone is interiorly supported by said duct. This cone ispositioned across the discharge end of the inner wall, so that the gason being deected across the air-ilow space by the cone will likewiseer1- train air at its speed and thereby cause greater lio-w thereofthrough said space.

Still further entrainment of air is achieved by providing for itsdeliection in the continuation space between the duct and the cone. Bymeans of inwardly projecting protuberances that extend into said spacefrom said duct wall the air traveling through the passageway strikesthese protuberances and in doing so is deflected into the gas streamexhausting from the inner gas-flow area, the gas stream in turn,increasing the velocity and volume of air being drawn through saidpassageway. Also, by means of co-functioning indentations in the sidesof the cone, extreme turbulence is set up in the gas-air mixture. Thelowered temperature of the mixed gas and air presents a lower pressurearea for the on-coming gas and Yair to rush into. This, in turn,invitesthe removal of more heat internally and externally from the innermanifold wall and thus promotes superior exhausting.

This duct and cone may be comprised of a heat-resisting, non-metallicsubstance having sound-deadening properties superior to that of metal. v

Also, to increase the supply of cooling air to the system, pressurizedambient temperature air may be supplied thereto by means of a fan'orpropeller, or by heading the air entrance duct into the wind created bythe passage of a vehicle therethrough. Y Y

A further advantage of lowering the temperature of the gas as speedilyas possible lies in the permanency of the inner manifold wall itself. Bymaintaining consistently lower temperatures in the exhaust system, themetal comprising the walls thereof would be subjected to less stress andpossible rupture. Under present operating conditions, manifolds get redhot, especially radial engine collector rings, and expand and contractto an alarming degree with alternate changes in temperatures. Sometimesas much as an inch occurs in the dimensions of a manifold, bothcircumferentially and longitudinally. Studs snap and clamps that joinsections together often burst. Safeguarding the manifold system fromsuch po tential danger is, therefore, an important object of thisinvention.

Other advantages offered by this internal-external cooling means willbecome apparent as the herein description proceeds.

Inthe drawings:

Fig. 1 is a side view of a radial engine, showing a tractorpropellerthat provides motion for air entering the duct that communicates withthe shroud wall and the space between the shroud and the inner open-endwall; also, the several individual pipes leading from the enginesexhaust ports and the conduit entrance portions which extend into thespace wherein cooling air is ilowing.

Fig. 2 shows, for ptuposes of clarity, an exaggerated viewof an exhaustmanifold system adapted to an inline automotive engine, individual pipesbeing shown in dotted outline for conveying the gas from the enginescylinders to the manifolds inner wall; also, entrance ends of theconduits for conveying air directly into the gas-How area. The shroudwall is shown in cross section.

Fig. 3 is a cross sectional view of the manifold system showing theouter shroud wall and, separated therefrom by spiders, the innergas-conveying wall. The wall-like inserts in which theconverging-diverging conduits are mounted are shown welded in position.Also shown is the cone element for deecting the gas from the gas-flowarea across the discharge end of the air space between the shroud andthe inner wall for suction of air through said space.

Fig. 4 shows a square form'of open-end wall with a plurality ofapertures in each of its sides for the reception therein of insertscarrying the converging-diverging conduits. A round open-end wall wouldhave appropriately contoured apertures for the same purpose.

Fig. 5 is a frontal view of an insert showing the dividedhalfconstruction with semi-apertures formed in each half for encompassingthe converging-diverging conduit which is, on assembly, welded in theinner wall. Upon assembly, too, the divided constructions are welded toeach other and the completed inserts secured in the apertures providedin the walls.

Fig. 6 is a top view of a square form of manifold system, showing theouter shroud wall, the inner open-end wall carrying inserts which, inturn, carry converging-diverging conduits for permitting the exhaust gasto entrain air most eciently into the gas-ow area. Spider means forspacing the inner open-end wall'from the shroud wall are also shown.

Fig. 7 is an end View of an individual insert having aconverging-diverging conduit mounted therein.

Fig. 8 is a view similar to that shown in Fig. 3, depicting theair-conveying ducts, the outwardly ared rim at the discharge end of theconduits for deflecting the exhaust gas therearound to promoteentrainment of cooling air. Serpentine arrows 13 indicate the -tortuoustravel of the gas to promote turbulence thereof due to its deflectionaround the diverging ends of the conduits, which deflection creates anegative pressure area across said diverging ends and promotes the ow ofcooling air into the gas-how area.

Fig. 9 is a view looking downward, taken on the line 9-9, Fig. 8,showing the inwardly extending rim of the diverging conduit ends andspider means separating the inner from the shroud wall.

Exhaust gas is conveyed from engine 1 through individual pipes 2 intogas-ow area 3 defined by open-end wall 4, Figs. l and 2. As shownclearly in Figs. 1, 2, 3 and 8, this open-end wall is spaced from outershroud wall 5 by means of spiders 6, which permit the ow of atmosphericair through space S. Shroud wall S may be connected to air intake duct7, illustrated in Fig. l, said duct being iitted with a bell mouth 7Awhich faces into the wash of propeller 8 and which is attached to shroudwall 5 by means of flange 15. As an alternative, shroud wall 5 may havean entrance end such as is shown at 5A, Fig.V 2, and have associatedtherewith a number of individual shroud walls 5B, Fig. 2; which AWallsspatially encompass exhaust pipes 2 that convey the gas from eachcylinder of the engine through wall 4. As another alternative, insteadof fan or propeller means being employed to ram air into space S, themanifold system may be mounted on a vehicle to head into the wind forincreasing the dlow of air through said space.

The inner and its accompanying shroud wall may have a round, square oroblong construction. For Yan equivalent area occupied by a roundconstruction, a square construction would offer more internal andexternal surface. A square construction is shown in Figs. 4 and 6,whereas a round construction is illustrated in Figs. 3, 8 and 9.

As shown in Fig. 4, a plurality of shouldered edges in wall 4 formapertures 9 in the inner wall. A similar type of appropriately conturedapertures may be formed in a round wall. Irrespective of the type ofconstruction employed a like number of matching shouldered inserts 10are formed to occupy said apertures.

These inserts initially are of divided construction, as shown in Fig. 5,and have openings 10A formed in each of the halves. These half-openingsencompass conduit 11 at the throat portion thereof and `are weldedthereto, as at 12, Figs. 3, 6 and 8; after which the insert lhalveswould be welded together to comprise a complete insert which may, inturn, be welded to the shouldered edges forming apertures 9.

Conduits 11 are of converging-diverging construction, the portion 11Athat protrudes outwardly from its respectlve insert Abeing shaped tointercept air owing through space S, while portions 11B Vextend inwardlyand diverge to promote suction of air across openings 11D by the gasowing at high velocity therearound. As shown in Figs. 3, 8 and 9, rightangular flanges 11C are formed at the discharge ends of divergingportions 11B to promote this maximum suction of air. Fig. 8 showsserpentine arrows 13, which carry small circles that indicate suction ofcooling air, whereas'the ow of gas around anged conduit ends 11C isillustrated by the small arrows 13A in Fig. 9.

In addition to the exhaust gas surrendering heat to co'oling airentrained inwardly as above described, means are also provided -wherebythe gas also entrains air directly between the inner and the shroudwalls fo'r cooling the inner wall by convection. Duct 16, Figs. 1, 2 and3,

is formed to be secured to shroud wall 5 at flange 17, being securedthereto by a plurality of bolts 18. Cone 14 is secured to duct wall 16by means of spiders 19, which permit the passage of exhaust gas and airtherethrough and which provide space -S between the cone and duct. Thiscone may have any desired shape for deecting the exhaust gas across thedischarge end of space S, thus imparting to the air the velocity of thegas-air mixture issuing from the gas-ow area defined by wall 4. Thepurpose of the cone being to deflect the gas whereby maximum suction ofair through space S may be achieved, it may be mounted at any desiredposition beyond the terminus of wall 4. Arrows 33 show the flow of thegas at this point, indicating the pickup of air from space S as perarrows 34, Figs. l, 2 and 3.

As illustrated in Fig. l, this cone may have a shape that terminates ata right angle to the entering end thereof to correspond with the contourof the duct wall. This duct, in turn, may terminate in a ange, as at 20,Fig. 3, whereby it may be coupled to' a device entitled RotaryTemperature-Reducing Exhaust Silencer, described in pending application,Serial No. 675,107, tiled July 30, 1957, for further processing beforethe gas is lfinally discharged to atmosphere.

To assist further in the flow of cooling air from atmosphere and theconsequent reduction of exhaust gas temperature, protuberances 21 aresecured to the inner surfaces o'f duct 16 to further deflect the mixtureof gas and air flowing through space S; also, indentations 22 areprovided in the sides of cone 14 to cause further turbulence of thegas-air mixture and promote through said turbulence still loweredtemperature of the discharging gas. If this system is mounted in anaircraft, flared end 16A of the duct would enhance still further thedischarge of said gas-air mixture to atmosphere.

Both duct 16 and cone 14 and protuberances 21 may be constructed of asubstance capable of withstanding the temperatures of the gas-airmixture without surrendering their shapes.

Fig. 2 indicates an exaggerated mounting of the manifold system of thisinvention on a -cylinder in-line engine 23, the gas leaving exhaustports 24 and being conveyed by pipes 2 into the gas-flow area deiined byinner wall 4. Individual shroud assemblies B are provided for a purposesimilar to that described hereinabove.

Fan assembly 25 may be employed in association with this engine in aframe construction 26, which carries ball bearings 27 to support shaft28. This fan may be driven by gearing or V-belt means, pulley 29 mountedon said shaft being connected by V-belt 30 to V-pulley 31 mounted oncrankshaft 32 of the engine.

Having described my invention, I claim:

1. An exhaust cooling and silencing means fo'r an internal combustionengine having a plurality of exhaust ports and driving an air propeller,said means comprising an internal-external air-cooled manifold formed byan inner open-end wall dening a gas-tiow area and a wall spaced fromsaid inner wall to comprise an open-end shroud to establish a passagewayfor the travel of ambient temperature air therethrough, a ductcommunicating with atmosphere for delivering air to the space betweensaid inner wall and said shroud, a pipe connected to each exhaust portand extending through said shroud and through said inner wall fordelivering exhaust gas under engine discharge temperature and pressureinto said gas-flow area, a plurality of apertures provided at spacedintervals in said inner -wall and a like number of wall-like insertsfo'rmed to t said apertures and be made secure to said wall, an open-endtubular conduit mounted in each of said inserts, each of said conduitshaving a portion that extends outwardly from said inserts into saidpassageway for intercepting said ambient temperature air, said portionconverging to form a throat for passage through said inserts, saidthroat having a cross-sectional area less than that of said convergingportion for permitting increased travel speed of said air through saidconduits, said conduits having a diverging portion extending inwardlyfrom said inserts for delivering said air to the center of said gas-flowarea.

2. The exhaust cooling and silencing means ydescribed in claim 1 whereinsaid inserts have a twin-half construction and o'penings in the halvesthereof that face each other for encompassing said conduits, saidconduits being made secure to said halves and said halves being madesecure to each other `for mounting in said apertures.

3. The exhaust cooling and silencing means described in claim 1 whereineach of said tubular conduits has a diverging end that extends into saidgas-dow area and defines an opening that faces in the direction oftravel O'f said exhaust gas, said end terminating in a right-angularflange extending toward the center of said gas-flow area for inducingsuction of air from said passageway into said area by the iiow of saidexhaust gas therearound.

4. An exhaust cooling and silencing means for an internal combustionengine having a plurality of exhaust ports and driving an air propulsionmeans, comprising an internal-external air-cooled manifold formed by aninner open-end wall dening a gas-dow area and an outer wall comprisingan openend shroud, each of said walls having an intake and a dischargeend, a space provided between said shroud and said inner -wall toestablish an airiow passageway, a duct for conveying air pressurized bysaid propulsion means into said passageway, a pipe connected to eachexhaust port and extending through said shroud and through said innerwall for delivering exhaust gas under engine discharge temperature andpressure into said gas-how area, a duct comprised of an openend Wallremovably secured to the discharge end of said shroud wall, a pluralityof protuberances extending inwardly from said duct wall into saidpassageway for deecting air into the gas stream discharging from saidgasiiow area, a co'ne having a number of indentations fOrmed in itssurface and a tapered entering and a tapered trailing end spatiallysupported by said duct, the entering end of said cone extendingpartially into the area dened by the discharge end of said inner walland said indentations being positioned in said cone surface to coactwith said protuberances for increasing turbulence in the air owingthrough said passageway.

References Cited in the file of this patent UNITED STATES PATENTS1,027,469 Forney May 28, 1912 1,370,197 De Bolotoi Mar. 1, 19212,396,208 Serre et al. Mar. 5, 1946 FOREIGN PATENTS 354,815 Italy Dec.9, 1937

